The use of short-term jobs (filled for under a year) by companies may be designed to achieve two objectives: flexibility and selection/motivation. In order to distinguish between these aims, the productivity of these jobs is compared with that of employees employed for under a year but remaining with the company and with that of workers employed for over a year. While short-term jobs prove to be more productive than others filled for a comparable length of time in the service sector, this differential is not present in the industrial sector. The use of short-term jobs does not appear to have the same meaning in this sector. In industry, recently employed employees seem to fill jobs with identical productivity and which are therefore similar in nature, whether or not they are asked to remain in the company. In services, employees filling a short-term position fill posts which are more immediately productive for the company. This may reflect the existence in these sectors of positions which must be filled for under one year, in order to respond to year-on-year variability in the company's activity. In any case, the fact that the productivity of these jobs is greater than or equal to others filled for a comparable length of time leads us to think that the use of short-term jobs is not mainly motivated by the companies' desire to select their employees or encourage them to work hard.